U.  S.  DEPARTMENT  OF  AGRICULTURE, 

DIVISION    OF    ENTOMOLOGY— BULLETIN    NO.    34,    NEW    SERIES. 

L.   O.    HOWARD,    Entomologist. 


Principal  Insects  Liable  to  be  Distributed 
on  Nursery  Stock. 


Prepared  Lender  the  Direction  of  the  Entomoi 


OGIST, 


NATHAN    BANltS, 

A msta nt  Entom olog ist . 


WASHINGTON: 

GOVERNMENT    PRINTING    OFFICE. 

1902. 


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LETTER  OF  TRANSMITTAL 


U.  S.  Department  of  Agriculture, 

Division  of  Entomology, 
Washington,  D.  C.,  April  29,  1902. 
Sir:  I  have  the  honor  to  transmit  for  publication  a  manuscript  pre- 
pared  by  Mr.  Nathan  Banks,  of  this  office,  in  which  are  considered  the 
principal  insects  liable  to  be  distributed  upon  nursery  stock.  The 
inspection  of  nursery  stock  under  State  laws  has  become  so  general 
throughout  the  United  States  that  the  desirability  of  some  publication 
of  this  sort  has  become  very  evident.  I  had  the  matter  in  mind  last 
autumn,  and  at  a  conference  of  the  official  horticultural  inspectors  for 
the  United  States,  held  at  Washington  October  11-13,  1901,  a  resolu- 
tion was  unanimously  passed  requesting  this  Department  to  prepare 
and  publish  an  article  on  those  nursery  pests  of  the  country  which 
are  capable  of  transmission  on  nursery  stock  to  the  injury  of  the  pur- 
chasers. Since  it  is  desirable  that  this  manuscript  shall  be  put  in 
available  shape  for  distribution  to  all  horticultural  inspectors  and  to 
all  nurserymen  and  others  immediately  interested,  I  recommend  that 
it  be  issued  as  Bulletin  No.  34,  new  series,  of  this  Division. 
Respectfully, 

L.  O.  Howard, 

Entomologist. 
Hon.  James  Wilson, 

Secretary  of  Agriculture. 


CONTENTS. 


Page. 

Introduction 9 

Tabular  statement  of  insects  upon  the  tree  in  winter 1 9 

Tubular  statement  of  insects  feeding  on  the  buds  and  young  leaves  in  early 

spring 10 

Hemiptera  (bugs,  scale  insects,  plant-lice) 10 

Family  Coccidse  (scale  insects) 11 

Table  of  scale  insects 11 

The  peach  lecanium 11 

The  oyster-shell  bark-louse 12 

The  scurvy  bark-louse 14 

Aspidiotus  ( circular  or  round  scales)   ; 14 

Table  of  Aspidiotus 15 

The  San  Jose  scale 15 

The  European  fruit  scale 18 

Putnam' s  scale 19 

The  cherry  scale 19 

The  walnut  scale 19 

The  greedy  scale 20 

The  grape  scale 20 

The  peach  scale 21 

The  rose  scale 23 

Family  Aphid;e  (plant-lice) 23 

Table  of  plant-lice 23 

The  woolly  apple  aphis 24 

The  black  peach  aphis 25 

Apple  plant-lice 26 

The  plum  plant-louse 26 

The  cherry  aphis 27 

Family  Psyllidse 27 

The  pear-tree  psylla 27 

Family  Membracidse.   28 

The  buffalo  tree-hopper 28 

Lepidoptera  (butterflies  and  moths) 29 

The  apple-tree  tent  caterpillar 29 

The  fall  web  worm 30 

The  browm-tail  moth 31 

The  leaf-crumpler 32 

The  white-marked  tussock  moth 32 

The  gipsy  moth ,  33 

Cankerworms 35 

The  peach-tree  borer 35 

The  peach  twig-borer 36 

The  bagworm 37 

Other  caterpillars 38 

5 


Coleoptera  (beetles,  weevils) 38 

The  round-headed  apple  tree-borer 39 

The  flat-headed  apple  tree-borer 40 

The  sinuate  pear-borer 40 

The  fruit-tree  bark-beetle. 42 

The  apple  twig-borer 43 

Acarina  (mites) 43 

The  pear-leaf  blister-mite 43 

Insects  infesting  fruits ....  =  „ 45 


ILLUSTRATIONS. 


Page. 

Fi(i.    1.  Lecanium  nigrofasciatum 12 

2.  Mytilaspis  pomorum 13 

3.  M ytilaspis  pomorum 13 

4.  Chionaspis  furfurus 14 

5.  Aspidiotus  perniciosus,  on  branch 16 

6.  Aspidiotus  perniciosus,  female 17 

7.  Aspidiotus  perniciosus,  on  fruit  and  branch 18 

8.  Aspidiotus  ostraeformis 19 

9.  Aspidiotus  juglans-regire 20 

10.  Aspidiotus  rapax 21 

11.  Diaspis  pentagona 22 

12.  Aulacaspis  rosrc  . . 22 

13.  Eggs  of  plant  louse 23 

1 4.  Schizoneura  lanigera 24 

15.  Schizoneura  lanigera,  work  on  roots 24 

16.  Aphis  persicpe-niger 25 

17.  Psylla  pyricola 27 

18.  Ceresa  hubalis 28 

19.  Clisiocampa  amerieana 29 

20.  Hyphantria  cunea 30 

21 .  Euproctis  chrysorrhea 31 

22.  Orgyia  leucostigma 33 

23.  Porthetria  dispar,  moth 33 

24.  Porthetria  dispar,  larva 34 

25.  Porthetria  dispar,  chrysalis „ 34 

26.  Alsophila  pometaria,  moths 35 

27.  Alsophila  pometaria,  stages _ . 35 

28.  Paleacrita  vernata,  moths 35 

29.  Paleacrita  vernata,  stages 35 

30.  Sanninoidea  exitiosa 36 

31.  Anarsia  lineatella 36 

32.  Thyridopteryx  ephemeneformis,  cases 37 

33.  Thyridopteryx  ephemeneformis,  insects 37 

34.  Tmetocera  ocellana,  larva 38 

35.  Tmetocera  ocellana,  work  of 38 

36.  Saperda  Candida 39 

37.  Chrysobothris  femorata 40 

38.  Agrilus  sinuatus,  stages 40 

39.  Agrilus  sinuatus,  work  of 41 

40.  Scolytus  rugulosus 42 

41 .  Amphicerus  bicaudatus 42 

42.  Rhagoletis  pomonella 44 

43.  Rhagoletis  cingulata 45 

7 


THE  PRINCIPAL  INSECTS  LIABLE  TO  BE  DISTRIBUTED  ON 

NURSERY  STOCK. 


INTRODUCTION. 

In  preparing  this  descriptive  catalogue  of  the  insects  liable  to  be 
transported  upon  nursery  stock,  it  has  appeared  that  there  is  a  great 
disparity  of  views  as  to  what  insects  should  be  included.  To  include 
only  such  as  are  known  to  be  very  destructive  would  exclude  a  great 
many  species  that  will  be  found  by  anyone  who  examines  a  tree  in  the 
fall  or  early  spring.  To  include  all  the  species  that  are  known  to  be 
found  in  any  stage  upon  fruit  trees  in  winter  would  make  the  list  too 
bulky.  Therefore,  all  species  known  to  be  of  more  than  local  interest 
have  been  treated.  Notes  on  the  species  infesting  fruits  are  added  at  the 
end.  The  insects  have  been  arranged  according  to  their  natural  orders, 
and  in  the  Hemiptera  (bugs,  scale  insects,  plant-lice)  according  to  the 
families.  In  the  Coleoptera  (beetles,  weevils)  and  Lepidoptera  (but- 
terflies and  moths),  such  an  arrangement  did  not  seem  desirable.  No 
account  of  the  remedies  to  be  recommended  or  used  is  given,  as  these 
differ  greatly,  according  to  locality  and  conditions,  and  the  various 
State  laws  specify  certain  treatments. 

It  will  be  a  great  help  to  those  interested  in  the  growth  and  sale  of 
young  fruit  trees  to  be  able  to  recognize  the  appearance  of  the  various 
insect  pests  during  the  winter;  therefore,  much  attention  has  been  paid 
to  this  phase  of  the  subject. 

In  using  this  bulletin  one  should  remember  that,  besides  the  insects 
here  treated,  there  may  be  upon  a  tree  other  insects  of  )ess  importance. 

TABULAR  STATEMENT  OF  INSECTS  UPON  THE  TREE  IN  WINTER. 

Insects  upon  the  roots: 

Forming  swellings  on  apple  roots "Woolly  aphis. 

On  peach  and  plum  roots Black  peach  aphis. 

Insects  upon  the  bark  of  trunk  or  branches: 

Plant-lice  or  aphids Woolly  aphis. 

Small  brown  clear-winged  insect  in  the  crevices  of  bark Pear  psylla. 

Scale  insects  or  bark-lice See  Coccidse. 

Caterpillars  in  cases  or  cocoons Fall  webworm,  bud  moth,  apple 

Bucculatrix,  codling  moth,  pistol-case  and  cigar-case  bearers. 

In  nests  or  bunches  of  shriveled  leaves  attached  to  branches Leaf-crumpler, 

and  brown-tail  moth. 

9 


10 

Insects  upon  the  bark  of  trunk  or  branches — Continued. 

In  a  case  or  bag  hanging  from  twigs Bagworm. 

Clusters  of  eggs  on  bark Cankerworms,  tussock  moth,  and  gipsy  moth. 

A  belt  of  eggs  around  twigs Apple-tree  tent  caterpillar. 

Single  small  blackish  eggs  often  in  groups  on  twigs  or  branches Plant-lice. 

Smaller  reddish  eggs Clover  mite. 

Insects  beneath  the  bark: 

Tiny  holes  usually  near  a  crotch,  each  covered  by  a  bit  of  frass Peach 

twig-borer. 

Small  brown  beetle  within  the  twig Apple  twig-borer. 

Small  holes  in  bark  of  trunk  or  larger  branches Fruit-tree  bark-beetle. 

A  gummy  exudation  of  sap  at  base  of  tree Peach  tree-borer. 

Discolored  spots  or  cracks  and  evidences  of  frass Round-headed  and 

flat-headed  apple  tree-borers,  and  sinuate  pear  borer. 

TABULAR  STATEMENT  OF  INSECTS  FEEDING  ON  THE  BUDS  AND 
YOUNG  LEAVES  IN  EARLY  SPRING. 

Feeding  on  the  buds  or  young  shoots Bud  worm,  peach  twig-borer,  leaf-crumpler, 

brown-tail  moth,  pistol-case  and  cigar-case  bearers. 
Feeding  upon  the  leaves: 

Plant-lice Apple  plant-lice,  plum  plant-louse,  and  cherry  aphis. 

Caterpillars  in  tents Apple-tree  tent  caterpillar. 

Hairy  caterpillars Tussock  moth,  brown-tail  moth,  gipsy  moth. 

Bare  caterpillars Canker  worms. 

A  blister  or  gall  upon  leaves Pear-leaf  blister-mite. 

Small  caterpillars  within  little  cases Pistol-case  bearer,  cigar-case  bearer, 

leaf-crumpler,  and  bagworm. 

HEMIPTERA  (BUGS,  SCALE  INSECTS,  AND  PLANT-LICE). 

The  members  of  this  order  obtain  their  food  (which  is  liquid)  by 
sucking  it  up  a  slender  tube  into  the  mouth  cavity.  This  tube  or 
beak  is  composed  of  several  needle-like  pieces  so  shaped  and  arranged 
that  they  inclose  a  minute  channel  up  which  the  liquid  food  is  drawn. 
The  beak  is  inserted  in  the  plant  often  to  some  distance  beneath  the 
surface.  The  members  of  this  order  do  not  pass  through  a  pupal  or 
chrysalis  stage  like  the  butterflies  and  moths,  but  there  is  an  approach 
to  it  in  the  males  of  the  scale  insects.  The  insects  of  this  order  to  be 
treated  are  arranged  in  four  families,  which  may  be  separated,  for 
our  purposes,  as  follows: 

The  insect  from  above  apparently  without  legs,  antennae,  or  wings,  and  fixed  to  the 

host  plant;  the  adult  male  (not  often  seen)  usually  has  two  wings Coccidae. 

( scale  insects) . 
The  insect  shows  distinct  legs  and  antennas,  and  often  four  wings. 

Most  of  the  specimens  wingless,  and  provided  with  two  small  tubes  or  cornicles 

(see  fig.  16)  near  tip  of  body;  not  hopping  when  disturbed Aphididae 

(plant-lice). 
Adult  always  winged,  without  the  cornicles;  hopping  when  disturbed. 

The  prothorax  not  enlarged,  with  hyaline  wings. Psyllidse. 

The  prothorax  greatly  enlarged;  wings  obscured Membraeidse. 


11 

FAMILY  COCCIDiE   (SCALE  INSECTS). 

The  scale  insects,  or  bark-lice,  are  readily  known  from  most  insects 
in  that  the  stages  commonly  seen  are  immovably  fixed  to  the  bark  or 
leaf,  and  show  no  outward  sign  of  legs  or  other  structures.  For  a 
short  time  after  birth  they  are  active,  crawling  creatures,  and  distribute 
themselves  over  the  surface  of  the  plant.  Having  selected  a  location, 
they  push  their  long  and  thread-like  beaks  deep  into  the  tree  and  pro- 
ceed to  suck  up  the  sap.  As  they  grow  the  protected  or  covered  bark- 
lice  secrete  a  waxy  substance  that  hardens  and  forms  the  scale.  When 
the  insect  molts  the  old  skin  or  exuvium  remains  attached  to  the  scale. 
The  shape,  color,  and  position  of  this  exuvium  is  of  great  value  in 
identifying  the  specie-. 

Their  small  size  and  similarity  of  appearance  makes  their  determina- 
tion difficult,  and  it  is  rarely  safe  to  determine  the  species  by  a  few 
individuals,  but  on  a  moderately  infested  branch  one  is  apt  to  find 
some  specimens  that  are  quite  characteristic  of  the  species. 

The  unprotected  bark-lice,  such  as  the  Lecaniums,  secrete  no  cover- 
ing scale. 

TABLE    OF    SCALE    INSECTS. 

1.  Soft  scales,  without  a  shield-like  covering,  very  convex,  on  peach  or  plum. 

Lecanium  nigrofascUitnni , 

2.  Armored  scales,  with  a  shield-like  covering  and  showing  an  exuvial  spot,  much 

less  convex  than  Lecanium 3. 

3.  The  exuvium  shows  as  a  circular  spot  situated  near  the  center  or  at  least  remote 

from  the  edge  of  the  scale;  the  adult  female  scale  more  or  less  circular,  rarely 
whitish  in  color Aspidiotus. 

4.  The  exuvium  showing  as  a  more  or  less  ribbed,  elliptical  spot  at  the  end  or  close 

tooneedge  of  the  scale;  scales  usually  whitish  in  color;  if  not,  then  of  an  oyster- 
shell  shape : 5. 

5.  Scale  brownish;  the  female  of  an  oyster-shell  shape,  male  ovate. 

Mytilaspis  pomorum. 

6.  The  scale  whitish,  female  not  oyster-shell  shaped,  male  scale  elongate 7. 

7.  The  female  scale  plainly  ovate,  much  longer  than  broad;  the  male  scale  having 

three  longitudinal  keels  (see  fig.  4,  <l ) Chionaspis  furfurus. 

8.  The  female  scale  is  irregularly  circular,  but  little  longer  than  broad;  the  male 

scale  with  one  median  keel 1*. 

9.  Exuvium  orange  or  bright  yellowish;  on  fruit  trees;  male  with  keel  rather  indis- 

tinct  Diaspis  pentagona. 

10.   Exuvium  pale  or  dull  yellowish;  on  raspberry  and  blackberry ;  male  with  distinct 
keel iulacaspis  rosse. 

THE    PEACH    LECANIUM. 

(Lecanium  nigrofascialum  Perg. —  fig.  1.) 

This  insect,  formerly  known  as  L.persicae,  is  (me  of  the  largest  of  the 
scale  insects,  being  about  one-tifth  of  an  inch  long  and  two  thirds  as 
wide.  It  is  elliptical  in  outline  and  strongly  convex.  It  is  usually  of 
a  dull  greenish-brown  color,  sometimes  distinctly  marked  with  darker 


12 

bands.  It  is  found  upon  the  branches  of  peach  and  plum,  more  rarely 
on  apple,  and  commonty  occurs  on  the  under  side  of  the  branch,  the 
upper  side  of  which  is  covered  with  a  black  fungus  that  grows  on  the 
honey -dew  dropped  by  the  Lecaniums  from  the  branch  above.  The 
females  pass  the  winter  in  the  adult  condition.  The  eggs  are  developed 
by  the  latter  part  of  May.  The  young  hatch  early  in  June  and  con- 
tinue for  fully  a  month  (June  10  to  July  15).  The  young  larvae  are 
flat,  uniformly  pale  yellow,  and  with  a  thin  marginal  rim.  The}r  become 
stationary  in  a  few  weeks.  By  the  middle  of  July  the  male  pupae  are 
developed,  and  by  the  22d  the  first  winged  males  appear.  There  is  but 
one  brood  a  year,  and  the  best  time  for  treatment  will' be  during  July. 


Fig.  l.—Lecanium  nigrofasc latum  Perg.:  aduUs  at  left,  young  at  right.    (Howard). 

There  is  another  species  of  Lecanium  (Z.  prunastri),  less  commonly 
found  on  plum.  The  female  is  much  like  that  of  the  peach  Lecanium, 
but  the  insect  passes  the  winter  in  the  larval  state,  not  maturing  till 
May.  The  young  hatch  in  July,  migrate  to  the  leaves,  and  in  the 
early  fall  return  to  the  branches,  where  they  pass  the  winter.  It  has 
rarely  been  found  in  this  country  outside  of  New  York  State. 


THE    OYSTER-SHELL    BARK-LOUSE. 

(Mytilaspis  pomorum  Linn. — figs.  2  and  3.) 

The  oyster-shell  bark-louse  is  one  of  the  best  known  enemies  of  the 
orchardist.  It  is  a  dark,  slightly  convex  scale,  elongate  and  usually 
curved  in  outline,  much  resembling  a  miniature  oyster  shell.  When 
crowded  upon  the  tree  they  are  apt  to  be  less  curved  and  often  quite 
straight.  The  elongate  exuvium  is  situated  at  the  small  end.  Its 
elongate  shape  and  dark  color  at  once  separate  it  from  all  other  com- 
mon orchard  scales.  The  eggs,  which  are  whitish  in  color,  are  deposited 
in  late  summer,  and  occupy  the  posterior  two-thirds'of  the  scale.  The 
female  dies,  but  the  scale  remains  to  protect  the  eggs  during  the 
winter.     The  young  hatch  in  Ma}^  or  early  June,  crawl  out  upon  the 


13 


Fig.  2.—MytUaspis pomorum:  a,b,  females;  c,  scales  on  twig;  d,  male  scale.     (Howard.) 


Fig.  Z.—Mytilaspis  pomoram:  a,  male;  c,  larva;  e,  female;  b  and  d,  details.     (Howard.) 


14 

twigs  and  small  branches,  and  locate  there  permanently.  In  a  day  or 
two  they  begin  the  formation  of  the  scale.  The  male  scale  is  much 
smaller  than  the  female,  elongate,  wider  behind  than  in  front,  and 
little,  if  any,  curved.  It  is  uncommon  on  apple,  but  often  found  on 
other  food  plants.  The  winged  male  insect  appears  in  midsummer. 
There  is  but  one  brood  a  year  in  the  North,  but  in  parts  of  the  South 
there  are  apparently  two  broods;  the  second  one  hatching  about  Sep- 
tember 1.  The  oyster-shell  bark-louse  is  widely  distributed  and 
attacks  a  great  variety  of  trees,  but  is  especially  partial  to  apple. 


THE    SCURFY   BARK-LOUSE. 


(Chionaspis  furfurus  Fitch — fig.  4. 


This  common  orchard  scale  is  readily  known  by  its  whitish  color  and 
ovate  form.  The  adult  female  scale  is  rather  flat,  irregularly  ovate  in 
outline,  with  the  yellowish  exuvium  at  the  apex.     The  life  history  is 

similar  to  that  of  the  oyster-shell 
bark-louse.  The  eggs  are  laid  in 
the  early  fall  and  occupy  the 
greater  part  of  the  scale.  The 
mother  dies  and  the  scale  re- 
mains on  the  tree  during  the 
winter  to  protect  the  eggs.  The 
young  hatch  during  the  latter 
part  of  May  or  early  in  June. 
The  male  scale,  which  is  often 
very  abundant,  is  much  smaller 
than  the  female,  snow-white  in 
color,  and  fully  twice  as  long  as 
broad,  with  nearly  parallel  sides 
and  three  keels  or  ridges.  The 
winged  male  insects  issue  in  Sep- 
tember. There  is  but  one  brood  in  the  North,  but  probably  two  or 
even  three  in  the  South.  The  scurfy  bark-louse  is  widely  distributed 
and  occurs  on  most  orchard  trees,  but  chiefly  on  apple  and  pear. 

Aspidiotus  (Circular  or  Round  Scales). 

To  this  genus  belongs  the  most  destructive  known  species,  the  San 
Jose  scale.  The  other  species,  however,  often  cause  much  damage. 
There  is  a  considerable  resemblance  among  the  various  species,  so 
that  it  is  difficult  for  sluj  inexperienced  person  to  determine  them. 
The  final  characters  that  separate  species  are  based  on  the  structure  of 
the  pygidial  plate  of  the  adult  female  scale.  To  observe  this  it  is 
necessary  that  a  specimen  be  boiled  in  caustic  potash  and  mounted  in 
balsam  on  a  glass  slide.  When  this  is  examined  under  a  microscope 
the  lobes,  spines,   hairs,   and  sinuations  of  the  margin  of  the  plate 


Fig.  4. — Chionaspis  furfurus:  a,  b,  infested  twigs;  c, 
female;  d,  male.    (Howard.) 


15 

appear  quite  distinctly.  Thus,  the  characters  that  may  be  used  in  the 
field  are  not  final  and  only  comparative,  and  great  care  must  be  exer- 
cised, especially  when  only  a  small  amount  of  material  is  available, 
and  any  doubt  can  be  settled  only  by  sending  the  material  to  some 
competent  authority  who  can  mount  and  microscopically  examine  the 
species. 

TABLE   OF   ASPIDIOTUS. 

1.  Scale  of  adult  female  circular,  with  exuvium  central,  dark-colored,  the  exnvium 

pale  yellowish  when  dark  waxy  outer  covering  is  rubbed  off;  scale  not  very  con- 
vex, about  2II,m  in  diameter;   half-grown   scales  are  nearly  black  and  show  a 

central  nipple  surrounded  by  one  or  two  depressed  rings pemiciosus  Comst. 

Scale  of  adult  female  not  circular,  the  exuvial  spot  at  one  side  of  the  center;  the 
half-grown  scales  usually  paler  and  without  the  central  nipple  surrounded  by 
depressed  ring 2. 

2.  Adult  female  scale  dark-colored,  about  2mui   in  diameter;  exuvial  spot  orange 

or  reddish  colored A.  forbesji,  ancylvs,  and  ostreseformis. 

Adult  female  scale  paler,  or  larger,  or  with  white  center 3. 

3.  Scale  of  adult  female  about  2mm  in  diameter,  yellowish  or  pale  brownish,  with  a 

white  center,  quite  flat;  on  grape uvx  (  Jomst. 

Scale  of  the  adult  female  very  convex,  about  2.>nmi  in  diameter,  of  a  uniform  drab 

or  yellowish-brown  color,  the  exuvial  spot  showing  reddish,  but  not  commonly 

exposed rapax  Comst. 

Scale  of  the  adult  female  large,  nearly  3mm  in  diameter,  Hat,  and  pale-grayish  in 

color;  the  exuvium  reddish  or  orange jugktns-regix  Comst. 

In  identifying  scale  insects  by  means  of  the  above  table,  scales 
should  be  examined  from  bark  or  fruit  as  clean  as  possible,  and  where 
the  scales  are  not  crowded  and  have  room  to  normally  develop.  When 
thickly  massed  they  lose  their  characteristic  shape  and  appearance, 
and  on  sooty  or  dirty  bark  they  are  discolored  and  abnormal. 

THE    SAN   JOSE    SCALE. 
[Aspidiotus  pemiciosus  Comstock — figs.  5,  (>,  and  7.) 

The  San  Jose  scale  is  known  to  every  orchardist  by  hearsay,  but 
few,  however,  can  distinguish  it  from  allied  scales,  such  as  ancyhis, 
y brbesi,  and  osi/reaefonnis.  On  badly  infested  trees  the  scale  presents 
the  appearance  of  dark  gray,  scurfy  patches.  The  individual  scale  is 
about  2mm  in  diameter,  usually  nearly  circular  in  outline,  of  a  grayish 
color,  with  the  central  darker  nipple  surrounded  by  one  or  more  quite 
distinct  yellowish  or  pale  grayish  rings.  When  the  scales  are  crowded 
the  outline  is  more  or  less  distorted.  In  none  of  the  allied  forms  is 
the  adult  female  scale  as  nearly  circular  as  in  the  San  Jose  scale. 
When  on  fruit  or  young  twigs  there  is  often  a  reddish  discoloration 
around  the  scale.  Putnam's  scale  and  the  cherry  scale  have  a  brighter 
colored  exuvium,  situate  one  side  of  the  center.  The  cherry  scale  is 
often  much  paler  than  the  San  Jose  scale.  The  European  fruit  scale 
has  an  exuvium  similar  to  the  San  Jose,  but  lacks  the  darker  nipple; 


16 

moreover,  the  exuvium  is  plainly  not  at  the  center  of  the  scale.  The 
male  of  the  San  Jose  scale  is  about  two  times  as  long  as  broad;  broader 
at  one  end  than  at  the  other,  with  a  large,  dark  exuvium,  showing  a 
central  nipple.  It  is  situated  toward  the  small  end  of  the  scale.  The 
male  of  the  European  fruit  scale  is  not  so  elongate,  and  the  exuvium 
is  but  little  darker  than  the  scale  and  nearer  to  the  small  end  than  in 
the  San  Jose  scale.  The  male  of  Putnam's  scale  is  as  elongate  as  that 
of  San  Jose,  but  has  an  orange  exuvium.  The  male  of  the  cherry 
scale  is  in  shape  much  like  that  of  the  San  Jose  scale,  but  the  exuvium 
is  of  a  brighter  yellow,  the  scale  usually  being  paler  than  the  San  Jose. 


CL 

Fig.  5. — Aspidiotus  pemiciosus:  a, 


infested  twig;  b,  view  of  infested  bark  magnified. 
Marlatt. ) 


(Howard  and 


In  general  the  adult  female  of  the  San  Jose  scale  may  be  distin- 
guished from  its  allies  by  the  more  circular  scale,  with  yellow  exuvium, 
when  exposed,  more  centrally  located,  otherwise  with  dark  nipple;  the 
male  by  similar  characteristics  of  exuvium  and  nipple.  But  the  San 
Jose  scale  is  most  easily  recognized  by  its  immature  scales,  which  are 
almost  black,  circular,  and  with  a  central  nipple  surrounded  by  one  or 
two  depressed  circular  rings.  Such  a  character  is  not  found  in  any 
other  of  the  allied  scales. 


17 

The  San  Jose  scale  attacks  all  of  our  orchard  trees,  but  appears  to  be 
most  destructive  to  pear  and  peach.  The  insect  is  represented  in 
winter  by  partly  grown  specimens  whose  development  was  stopped  by 
the  cold  weather.  They  resume  growth  in  the  early  spring;  the 
males  soon  appear,  mate  with  the  females,  and  the  latter  give  birth  to 
living  young.  At  Washington,  D.  C,  this  time  is  about  the  middle 
of  May,  and  the  young  continue  to  appear  for  about  six  weeks.  The 
larva  crawls  off  a  little  way.  settles,  and  within  two  days  begins  the 


Fig.  6.—Aspidiohts pernicio&us:  a,  female;  b,  margin  of  pygidium  magnified.     (Howard  and  Marlatt.) 

secretion  of  its  scale.  This  young  scale  is  at  first  white  with  a  swell- 
ing in  the  center.  If  it  is  situated  on  green  tissue  it  is  apt  to  pro- 
duce a  redness.  In  a  few  days  the  pale  scale  becomes  nearly  black, 
with  a  central  nipple  surrounded  by  one  or  two  depressed  rings.  This 
form  is  very  characteristic  of  the  species.  In  about  twenty-five  days 
another  brood  of  males  appears,  and  in  thirty  days  the  females  become 
adult.  At  about  thirty -five  or  forty  days  of  age  the  females  begin  to 
give  birth  to  living  young.  Since  one  of  these  mother  scales  may 
have  been  born  six  weeks  before  another,  it  results  that  there  is  a 

24842— No.  34—02 2 


18 

confusion  of  generations  throughout  the  summer,  breeding  constantly 
going  on  until  late  fall.  The  number  of  broods  will  thus  depend  upon 
the  lenp'th  of  the  season. 


YiG.l.—Aspidlotaspcrniciosus:  Infested  fruit  and  branch,  and  enlarged  scales.     (Howard.) 


THE    EUROPEAN    FRUIT    SCALE. 

(Aspidiolus  ostrefeformis  Cnrtis — fig.  8.) 

This  species  can  usually  be  readily  separated  from  the  San  Jose 
scale  by  the  characters  mentioned  under  that  species,  but  it  is  practi- 
cally impossible,  without  making  a  microscopic  mount,  to  distinguish 
it  from  Putnam's  scale  and  the  cherry  scale.  The  cherry  scale,  espe- 
cially when  on  cherry,  is  more  shining  and  often  shows  a  grayish 
margin.  The  European  fruit  scale  occurs  on  all  orchard  trees,  but 
only,  so  far  as  known,  in  certain  Northern  States.  The  winter  is 
passed  by  the  partly  grown  specimens,  which  become  mature  toward 
the  last  of  June,  and  soon  begin  to  give  birth  to  living  }^oung.  The 
young  continue  to  appear  for  several  weeks.  There  appears  to  be  but 
one  brood  a  year,  at  least  in  the  Northern  States. 


19 


PUTNAM  S    SCALE. 
(Aspidiolus  ancylus  Putnam,  i 

This  scale  is  widely  distributed  and  attacks  all  orchard  trees.  In 
general  appearance  it  is  like  the  San  Jose  scale,  but  at  once  known  by 
the  exposed  orange  exuvium,  the  less  circular  scale,  and  by  the  half- 
grown  young  having-  no  depressed  ring  around  the  nipple.  It  can  be 
separated  from  the  European  fruit  scale  and  from  the  cherry  scale 
only  by  a  microscopic  examination  of  mounted  specimens.  It  is  usu- 
ally much  darker  than  the  cherry  scale,  the  exUvium  usually  a  brighter 
orange,  and  the  scale  more  conical  than  that  species.  Specimens  vary, 
however,  a  great  deal  in  these  points. 
The  insect  winters  in  a  nearly  full- 
grown  condition.  The  males  appear  in 
April,  soon  pair  with  the  females,  and 
the  latter  deposit  eggs  in  the  late  spring 
or  early  summer.  The  }roung  begin  to 
hatch  early  in  July  and  continue  dur- 
ing the  month.  There  is  but  one  brood 
a  }Tear. 

THE    CHERRY    SCALE. 
(Aspidiotus  forhesi  Johnson. ) 

This  scale  is  similar  to  Putnam's  and 
to  the  European  fruit  scale,  but  some- 
times, especially  on  cherry,  it  is  more 
shining,  and  presents  a  gray  rim  around 
the  scale,  which  is  commonly  flatter 
than  the  allied  species.  It  attacks  all  orchard  trees,  but  is  rarely  com- 
mon. It  winters  partly  grown,  like  its  allies.  The  male  issues  in 
April.  The  eggs  are  laid  in  April  or  earl}r  May,  the  young  hatching 
during  May  and  part  of  June.  There  appears  to  be  two  broods  a  year, 
the  males  of  the  second  brood  issuing  during  the  latter  part  of  July 
and  the  young  during  August  and  September. 


Fig.  8. — Aspidiotus  ostrexformis:  a.  scales 
on  twig;  b,  natural  size;  c,  immature 
stage:  <l,  female:  e,  male;  /and  g,  in- 
side of  scales.     I  Marlatt.) 


THE    W'ALNUT    SCALE. 
(A&pidiotus  juglans-regite  Comstock — tig.  9.) 

This  insect  is  at  once  recognized  by  the  large  size  of  the  adult  female 
scale,  it  being  the  largest  of  our  species  of  the  genus,  the  scale  often 
being  3mm  in  diameter  (one-twelfth  inch),  while  the  San  Jose  scale  is 
scarcel}T  2mm  in  diameter.  The  adult  female  scab4  is  irregularly  circu- 
lar in  outline,  quite  flat,  and  of  a  pale  grayish  or  dirty- white  color. 
The  exuvial  spot  is  reddish  or  orange  and  situated  one  side  of  the  cen- 
ter. The  scale  often  appears  to  be  less  closely  attached  to  the  bark 
than  with  the  other  species  of  this  genus.     The  male  scale  is  elliptical 


20 

and  much  smaller  than  the  female.  The  adult  female  scale  hibernates, 
and  deposits  eggs  in  early  spring.  The  males  from  them  issue  early 
in  June.  Eggs  are  deposited  again  in  June,  so  that  there  appears  to 
be  two  or  possibly  three  broods  in  the  South.  This  species  is  not 
abundant,  but  liable  to  be  found  on  almost  any  orchard  tree. 


Fig. 


■Aspidiotus  juglans-regix:  a,  female;  b,  male;  c,  pupa;  d,  e,  infested  twigs.     (Howard.) 


THE    GREEDY    SCALE. 

(Aspidiotus  rapax  Comstock — fig.  10.) 

This  is  quite  a  large  species,  readily  distinguished  from  the  others 
we  have  treated  by  its  very  convex  scale  and  uniform  drab  or  yellow- 
ish-brown color,  except  for  the  dark  brown  exuvium  which  often  shows 
near  the  center.  The  adult  female  scale  is  less  circular  than  most  of 
the  other  species,  and  does  not  always  show  the  exuvial  spot,  which  is 
at  one  side  and  covered  with  a  film  of  secretion.  The  male  scale  is  much 
smaller,  and  elliptical  in  outline.  The  young  are  nearly  circular,  with 
a  central  nipple  often  surrounded  by  a  pale  gray  ring.  This  scale 
is  ver}^  abundant  in  California  and  has  spread  somewhat  eastward, 
especially  in  the  South.  It  attacks  various  orchard  trees,  but  more 
commonly  the  orange.  It  is  a  scale  that  is  liable  to  be  found  more 
commonly  in  the  future,  and  orchardists  should  be  on  the  lookout  for 
it.     The  greedy  scale,  in  California,  winters  in  all  stages. 


THE    GRAPE    SCALE. 

(Aspidiotus  uvx  Comstock. ) 


This  is  a  more  or  less  elliptical  scale,  with  the  exuvium  rather  nearer 
one  end.  It  has  a  yellowish  or  pale  brownish  color,  with  a  whitish 
center  near  the  exuvium,  the  latter  of  a  pale  yellow.  The  scales  are 
often  found  in  a  longitudinal  row,  and  rarely  infest  both  sides  of  the 


21 

same  branch.  It  winters  in  the  ego-  stage.  The  young-  hatch  in  May; 
the  males  issue  in  the  summer.  There  is  but  one  brood  a  year.  It  is 
practically  confined  to  the  grape,  but  has  been  found  on  a  few  other 

plants,  and  may  spread  to  fruit  trees. 


Fig.  10. — Aspidiotus  rapax.     Scales  mi  twigs,  and  enlarged.     (Howard.) 

THE    PEACH    SCALE. 

{Diaspis  pentagvna  Targ.  Tozz. — fig.  11.) 

The  peach  scale,  sometimes  known  as  the  "whitewash  scale."  is  of  a 
grayish  white  color,  rather  flat  and   irregularly  circular  or   slightly 


Fig.  11.— Diaspis  pentagona;  u.  infested  branch;  h,  female;  c,  male;  d,  group  of  males.    (Howard.) 

ovate  in   outline,  never  as   elongate   as  the   scurfy   bark-louse.     The 
exuvium   is  often  a  little  way  from   the  margin,  and   is  yellowish  or 


22 

orange  in  color.  Its  pale  color  and  elongate  exuvium  will  readily 
separate  it  from  all  other  scales  on  orchard  trees.  The  insect  passes 
the  winter  with  the  mature  females  and  the  male  scales.  The  males 
hatch  in  early  spring.  The  eggs  are  laid  early  in  May,  and  the  larvae 
hatch  in  about  ten  days.  The  males  again  commence  to  issue  by 
the  middle  of  June,  and  the  females  begin  egg-laying  by  the  end  of 
June.  The  second  generation  is  full  grown  by  the  middle  of  August, 
and  these  in  time  soon  begin  to  lay  eggs  for  the  brood  that  will  winter 
as  mature  females  and  undeveloped  males. 


Fig.  12. — Aulaeaspis  rosse ;  1,  infested  branch;  la,  female;  lb,  male.     (Comstock.) 

The  male  scale  (fig.  11,  c,  d)  is  elongate,  about  three  times  as  long 
as  broad, ,  slightly  wider  behind  than  in  front,  with  a  median  keel,  and 
snow  white  in  color.  The  male  scales  appear  to  be  most  numerous  on 
the  lower  parts  of  the  branches  and  near  the  base  of  the  trunk  and 
often  so  matted  as  to  make  the  trunk  or  lower  branches  absolutely 
snow  white.  The  peach  scale  is  becoming  common  in  many  of  the 
Southern  States  and  as  far  north  as  Pennsylvania.  It  infests  plum, 
cherry,  and  peach,  and  less  commonly  other  plants. 


23 


THE    ROSE    SCALE. 

(Aulaeaspis  rosae  Sandberg — fig.  12.) 

This  species  is  similar  to  the  peach  .scale,  and,  indeed,  the  easiest 
way  to  distinguish  between  them  is  by  their  host  plants.  The  peach 
scale  does  not  affect  the  host  plants  of  the  rose  scale,  which  are  roses. 
raspberry,  and  blackberry.  The  scale  covering  is  much  more  thin  and 
delicate  and  the  exuvium  is  usually  of  a  paler  or  duller  yellow  than 
in  the  case  of  the  peach  scale.  The  keel  or  ridge  of  the  male  is  more 
distinct.  The  life  history  of  this  species  does  not  appear  to  be  well 
known  in  this  country.  It  winters,  as  a  rule,  in  the  eg^  as  far  north 
as  New  Jerse}T;  but  mature  females  and  immature  females  and  males 
may  be  found  in  winter.  In  the  early  spring  one 
often  finds  the  female  scales  surrounded  by  a  radiate  ,flT 

row  of  male  scales.     It  is  probable  that  there  is  more  A/\Ll 

than  one  brood  in  a  year,  at  least  in  the  South.  '    j^ 

The  plant-lice  are  small,  sluggish  insects  found  on 
the  under  surface  of  leaves  or  on  the  bark  and  roots.      W§^ 
Most  of  the  individuals  have  no  wings,  but  at  times      ^ 
one  finds  some  specimens  with  delicate  transparent       %        Jj^i 
wings  laid  roof -like  over  the  body.     They  all  have  ^| 

distinct  legs,  a  pair  of  moderately  long  antenna?,  and 
usually  quite  prominent  eyes.  They  occur  in  colo- 
nies, and  by  their  numbers  often  do  a  considerable 
amount  of  damage.     The  eggs  are  found  on  trees  in  jgj 

winter  situated  near  the  base  of  twigs  and  buds.  (See 
fig.  13.)  Thev  are  minute,  oval,  or  elliptical  shining  fig.  13.— Eggs  of  a 
black  objects/  During  the  warm  part  of  the  year  the  ^^)°ntwig' 
females  produce  living  young,  so  that  one  individual 
may,  in  a  few  months,  be  the  parent  of  a  large  colony.  Many  of  the 
species  secrete  a  sweetish  liquid  from  two  pre-apical  tubes  or  cor- 
nicles. This  liquid  is  known  as  honey-dew,  and  attracts  other  insects, 
especially  ants. 

TABLE    OF    PLANT-LICE. 

A.  Plant-lice  on  the  bark  or  roots: 

With  a  whitish,  woolly,  or  cottony  covering Schizoneura  lanigera. 

Without  such  covering \j>hi*  persicae-niger. 

B.  Plant-lice  on  the  leaves: 

With  bluish-white  mealy  powder;  on  plum Hyalopterus  pruni. 

Dark  brown ;  on  cherry Myzus  a  rasi. 

Green,  or  faintly  reddish;  on  apple Iphis  mali  and  A.  sorbi. 


24 


THE    WOOLLY    APPLE    APHIS. 

(Schizonrura  lanigera  Hausmann — figs.  14  and  15.) 
One  often  notices  on  the  trunk  or  larger  branches  of  the  apple 


Fig.  li.—Schizoneura  lanigera;  a,  agamic  female;  &,  larva;  c,  pupa;  d,  winged  female.     (Marlatt.) 

small,  bluish-white,  ilocculent  patches  of  a  woolly  substance,  which 

indicate  the  presence  of  this  insect. 
This  cottony  substance  is  a  wax-like 
excretion  clinging  to  the  posterior 
parts  of  a  small,  reddish -brown 
wingless  aphis.  It  is  not,  however, 
this  form  on  the  trunks  that  causes 
injury.  This  aerial  form  is  but  the 
indication  that  there  are  other  speci- 
mens, under  the  ground  and  feeding 
on  the  roots  of  the  tree.  It  is  the 
latter  form  that  seriously  affects  the 
vitality  of  the  tree.  Upon  the  trunk 
the  lice  often  cause  a  roughening 
of  the  bark,  especially  on  the  new 
growth  around  scars  made  by  prun- 
ing. On  the  roots  the  lice  cause 
hard  and  large  knots,  which  eventu- 
ally produce  a  "club-footed"  con- 
dition of  the  roots.  Such  trees 
usually  show  their  weakness  by  the 
fewer  and  duller  colored  leaves. 

The  woolly  aphis  is  practically 

confined  to  the  apple,  but  there  are 

a  few  varieties,  such  as  the  Northern 

against  its  attacks.     The  lice  com- 


Fig.  15. — Schizoneura  lanigera;    a,  b,  work  on 
roots;  c,  a  louse.     (Marlatt.) 

Spy,  that  appear  to  be  immune 


25 

inonly  found  on  the  trunk  and  roots  in  summer  are  the  wingless, 
agamic  females.  They  give  birth  to  living  young,  and  continue  to  do 
so,  possibly  for  several  years.  In  spring  some  of  the  root-lice4  will 
crawl  up  the  trunk  and  continue  to  breed  there  till  fall.  The  colonies 
of  lice  on  the  trunk  give  rise  to  winged  and  migratory  females.  These, 
when  they  locate,  give  birth  to  wingless  male  and  female  lice,  and  each 
female  deposits  a  single  winter  egg  in  a  crevice  of  the  bark.  This  egg 
will,  in  the  spring,  hatch  into  a  female  which  will  start  a  new  colony 
of  wingless  lice  on  the  trunk.  Some  of  these  will,  in  the  summer, 
crawl  down  upon  the  roots  and  continue  to  breed  there.  In  the  north 
the  colonies  on  the  trunk  are  apt  to  be  killed  out  by  the  severe  cold 
weather,  but  in  warmer  latitudes  many  of  them  live  through  the  winter, 
particularly  if  they  are  protected  by  a  piece  of  bark. 

THE    BLACK    PEACH    APHIS. 

{Aphis  persicse-7iiger  E.  F.  Smith — fig.  16.) 

This  insect,  like  the  woolly  apple  aphis,  does  its  great  injury  under- 
ground. Its  ravages  on  the  roots  of  peach  give  a  sickly  appearance  to 
the  foliage  of  the  affected  tree,  the  leaves  often  being  light  green  or 


Fig.  16.— Aphis  persicx-niger;  winged  specimen.     (J.  B.  Smith.) 

yellowish  in  color,  and  their  edges  somewhat  rolled.  The  wingless 
lice  on  the  roots  are  of  a  dark-brown  color.  They  breed  there  con- 
tinuously without  producing  males  or  eggs.  Early  in  the  spring  some 
of  the  root-lice  crawl  up  the  trunk  of  the  tree  and  locate  on  the  young 
twigs.  Here  the  winged  form  develops  and  migrates  to  other  trees  to 
found  other  colonies.  The  winged  insect  is  of  a  shining  black  or  very 
dark  brown  color,   the   tibia?   of   the   legs    being   mostly   yellowish. 


26 

Toward  midsummer  many  of  the  lice  on  the  twigs  crawl  down  into  the 
ground  and  locate  upon  the  roots. 

APPLE    PLANT-LICE. 

The  foliage  of  apple  trees,  particularly  of  young  trees,  often  appears 
curled,  and  sometimes  discolored.  This  curling  is  produced  by  colo- 
nies of  plant-lice.  These  lice  secrete  a  sticky  liquid  known  as  honey- 
dew,  which  falls  on  the  leaves  below.  A  black  fungus  grows  upon  the 
leaves  covered  by  the  honey-dew,  and  this  checks  their  growth.  There 
are  several  of  these  plant-lice  that  attack  the  leaves  of  apple;  two  of 
them  are  greenish  in  color,  another  has  a  reddish  tinge. 

The  commoner  of  the  two  green  species  is  known  as  Aphis  mali 
Fitch,  (probably  Aphis  annum  Oest).  Its  life  history  is  about  as  fol- 
lows: The  eggs  are  laid  on  the  tree  in  the  fall,  partly  hidden  in  crev- 
ices of  the  bark;  the  young  hatch  from  these  eggs  in  early  spring,  and 
grow  into  wingless  and  sexless  lice,  known  as  "stem-mothers,"  which 
produce  living  young;  these  young  become  winged,  and,  in  the  early 
summer,  migrate  to  grasses,  where  they  increase  during  the  summer. 
In  the  fall  they  develop  a  set  of  winged,  sexless  lice,  which  migrate 
back  to  the  apple  and  give  birth  to  sexed  individuals;  these  pair,  and 
the  female  lays  her  eggs. 

The  other  green  species  is  Aphis  mali  Koch.  It  passes  its  entire 
life  history  upon  the  apple.  The  eggs  are  laid  in  the  late  fall.  They 
are  black,  and  occur  generally  on  the  trunk  and  branches.  In  early 
spring  the  young  hatch  from  these  and  grow  into  stem-mothers.  These 
produce  living  young  for  a  number  of  generations.  Many  of  these  of 
the  first  two  generations  become  winged,  fly  to  other  apple  trees,  and 
there  start  colonies.  In  October  sexed  specimens  are  produced,  and 
the  female  lays  the  eggs  that  are  destined  to  pass  the  winter. 

The  other  apple  plant-louse  is  A.  sorbi  Kalt.  It  is  distinctly  tinged 
with  red,  and  the  wingless  forms  have  a  whitish  powdering  on  the 
body.  This  species  has  a  life  history  similar  to  that  of  Aphis  mali 
Fitch.,  but  it  is  not  known  what  plants  serve  as  its  summer  hosts. 

THE   PLUM   PLANT-LOUSE. 

{Hyaloptevus  pruni  Fabr. ) 

This  insect  winters  in  the  egg  state.  The  young  on  hatching  in 
spring  go  to  the  under  surface  of  the  leaf  and  there  multiply  rapidly. 
Their  bodies  are  covered  by  a  bluish-white  mealy  powder.  Winged 
specimens  are  occasionally  developed  which  migrate  to  other  trees. 
They  feed  on  the  plum  all  summer,  but  some  specimens  are  said  to 
migrate  to  grass  in  early  summer.  In  the  fall  the  winter  egg  is 
attached  to  a  plum  twig,  usually  at  the  base  of  a  bud.  At  times  they 
do  considerable  damage  to  young  plum  stock. 


27 


THE    CHERRY    APHIS. 

(  Myzus  cerasi  Fabr. ) 

This  aphis  often  causes  the  leaves  of  the  cherry  to  become  crumpled 
and  rolled,  and  on  young  trees  sometimes  does  serious  damage.  The 
winged  and  wingless  insects  are  both  of  a  dark  brown  color,  and  look 
much  like  the  black  peach  aphis.  The  c^^  are  laid  in  the  fall  on 
the  branches  at  the  base  of  buds  and  in  crevices  of  the  bark.  The 
young  hatch  from  them  in  the  spring  when  the  buds  begin  to  swell. 
crawl  out  upon  the  buds  and  growing  leaves,  and  develop  into  stem- 
mothers,  which  give  birth  to  living  young.  This  is  kept  up  all  sum- 
mer until  the  fall,  when  the  sexes  appear  and  the  female  deposits  her 
eggs.  A  number  of  winged  migrants  are  developed  in  the  spring 
generations,  which  serve  to  spread  the  species.  The  insects  usually 
become  very  abundant  by  June,  but  in  midsummer  they  are  not  as 

common. 

FAMILY  PSYLLIDiE. 

THE    PEAR-TREE    PSYLLA. 

(Psylla pyricola  Forster — fig.  17.) 

This  insect  is  closely  related  to  the  plant-lice,  but  readily  known  by 
its  longer  antenna1  and  its  ability  to  hop.     Its  color  is  reddish,  with 


Fig.  17.— Psylla  pyricola;  greatly  enlarged.     ( Maria tt.) 

some  black  markings,  and  with  clear  wings  laid   roof -like  over  the 
body.     When  disturbed,  it  hops  and  flies  away. 


28 


The  insect  is  widely  distributed  in  the  East,  but  usually  is  not  abun- 
dant enough  to  seriously  injure  the  ttree.  When  they  become  excess- 
ively abundant  they  cause  the  leaves  and  fruit  to  dr}^  and  fall.  The 
adult  insect  hibernates  in  crevices  of  the  bark.  These  overwintering 
specimens  are  brownish-black  in  color,  with  bronzy  eyes.  The}^  emerge 
from  their  hiding  places  in  the  early  spring,  mate,  and  the  female  begins 
to  lay  eggs  before  the  leaves  are  out.  The  eggs  are  placed  singly  or 
in  groups  in  crevices  of  the  bark  of  the  twigs  or  in  old  leaf  scars,  and, 
when  the  leaves  have  unfolded,  upon  the  leaves  themselves.  The  larvae 
hatch  in  about  two  weeks  and  begin  to  suck  the  juices  from  the  leaves 
and  petioles.  They  at  once  commence  to  excrete  hone}r-dew,  and 
when  the  insects  are  extremely  numerous  the  amount  of  liquid  secreted 

is  enormous  and  fairty  rains  from  the 
tree.  A  black  fungus  grows  on  the 
honey-infested  leaves  and  tree,  so  that 
the  whole  soon  has  a  smoked  appear- 
ance. In  about  thirty  days  the  larva 
becomes  adult.  Development  contin- 
ues all  through  the  summer,  and  there 
may  be  as  many  a  live  broods  if  the 
season  be  long  enough.  It  is  only 
known  to  attack  the  pear. 

FAMILY  MEMBRACIDiE. 
THE    BUFFALO    TREE-HOPPER. 

(Ceresa  bubalus  Say — fig.  18.) 

Upon  young  fruit  trees,  particularly 
the  apple,  one  sometimes  sees  a  series 
of  oval  or  elliptical  scars  that  disfigure 
and  weaken  the  branches  and  render 
them  liable  to  other  insect  attack. 
These  scars  are  the  results  of  the  work  of  a  curious  insect,  the  buffalo 
tree-Lopper.  It  is  a  grass-green,  triangular  insect  that  hops  and  flies 
away  when  disturbed.  The  pronotum  of  the  thorax  is  enlarged,  as 
with  others  of  this  family,  to  cover  the  head  and  most  of  the  abdomen. 
The  anterior  corners  of  the  pronotum  project  laterally  into  acute 
angles.  In  August  and  September  the  adult  insects  ma}^  be  found  on 
the  trees  engaged  in  oviposition.  The  female  cuts  the  bark  with 
her  ovipositor  in  two  nearly  opposite  curved  slits,  so  that  the  bark 
between  is  cut  loose.  Beneath  each  slit  she  deposits  a  series  of  from 
6  to  12  eggs.  These  eggs  hatch  in  the  spring.  The  dead  piece  of 
bark  falls  out  and  leaves  the  elliptical  scar,  which  enlarges  with  the 
subsequent  growth  of  the  twigs  and  becomes  an  inviting  point  for 
the  attack  of  other  insects.     There  is  but  one  brood  each  year. 


Fig.  18.— Ceresa  bubalis:  a,  insect;  b,  recent 
punctures;  c,  eggs;  e,  old  scars.    (Marlatt.) 


29 
LEPIDOPTERA  (BUTTERFLIES  AND  MOTHS). 

The  caterpillars  and  cocoons  of  these  insects  are  known  to  all.  The 
caterpillars  differ  from  the  grubs  of  beetles  in  that  they  have  on  the 
under  side  two  rows  of  pro-legs — fleshy,  wart-like  structures  that  serve 
to  support  the  posterior  part  of  the  body.  The  injuries  caused  by 
these  insects  are  made  by  the  caterpillar.  These  have  biting  mouth- 
parts  that  nip  out  tiny  pieces  of  the  leaf  or  wood,  which  is  then 
chewed  and  swallowed.  The  more  injurious  forms  that  are  liable 
to  be  transported  on  nursery  stock  may  be  arranged  as  follows: 

1.  Feeding  within  the  trunk. Peach-tree  borer. 

Feeding  within  the  twigs  <>r  leaf-shoots Peach  t  wig-borer. 

Feeding  upon  the  leaves 2. 

2.  The  insect  covered  by  a  case Bagworm,  leaf-crumpler,  pistol-case  bearer, 

cigar-case  bearer. 
The  insect  not  covere<  1   by  a  case 3. 

3.  Making  tents  or  nests Apple-tree  tent  caterpillar,  fall  webworm,  brown- 

tail  moth,  leaf-crumpler,  and  bud  moth. 
Without  tents 4. 

4.  Hairy  caterpillars Tussock  moth,  gipsy  moth. 

Bare  caterpillars Cankerworms. 

THE    APPLE-TREE    TENT    CATERPILLAR. 
(Clisiocampa  americana  Ilarr — fig.  L9.  I 

%v; ■  ^  ~  -r^mim?         -P.  ■  -~M{ 

tm 

HP 

e  r-  */ 

Fig.  19.— Clisiocampa  americana:  a,  b,  caterpillars;  c,  egg-mass,  d  pupa;  e,  female.  /.  male.    I  Riley.) 

The  webs  or  tents  of  this  caterpillar  are  frequently  found  on  orchard 
and  nursery  trees  in  May  and  June.     The  caterpillars  use  this  tent  as 


30 


a  common  home,  where  they  retire  at  night  and  remain  during  cloudy 
days.  Each  clear  morning,  at  about  8  o'clock,  they  go  out  along  the 
branches  to  the  leaves  for  feeding.  The  amount  of  damage  done  will 
depend  a  great  deal  upon  the  number  of  tents  upon  the  tree.  The 
eggs  are  laid  in  masses  of  200  or  300  arranged  in  a  broad  belt  around 
the  twig.  (See  fi.g.  19,  c.)  Each  end  of  this  belt  tapers  off  to  the  twig, 
which  character  serves  to  distinguish  it  from  similar  egg-clusters  of 
certain  other  moths.  Each  mass  is  covered  with  a  glistening  sub- 
stance that  protects  it  from  the  rain.  The  }^oung  caterpillars  hatch 
during  the-  latter  part  of  April  or  earty  in  May,  at  about  the  time 
when  the  leaves  are  expanding.  They  immediately  begin  to  feed  on 
the  leaves  near  by  and  to  unite  them  into  their  tent,  which  is  enlarged 
as  the  caterpillars  grow.  The  full-grown  larva  is  nearly  2  inches  long, 
hairy  and  black,  with  a  white  stripe  along  the  back.     On  each  side  of 

this  is  a  row  of  short,  yel- 
low streaks;  there  are  also 
pale  lines  on  the  sides  of  the 
body.  The  under  side  is 
nearly  black.  When  ready 
to  pupate  the  caterpillar 
seeks  some  protected  spot 
and  there  spins  its  yellowish 
cocoon,  and  soon  changes 
to  a  brown  chrysalis.  The 
moth,  which  is  brown,  with 
oblique  white  bands  across 
the  forewings,  emerges  in 
a  week  or  so  and  deposits 
her  egg-mass  and  dies. 
There  is  but  one  brood  a 
year. 

THE    FALL    WEBWORM. 

(Hyphantria  cunea  Dru. — fig.  20. ) 

During  the  summer  and 
early  fall  webs  or  tents  sim- 
ilar  to  those  of  the.  apple- 
tree  tent  caterpillar  are 
often  seen  among  the  terminal  branches  of  fruit  trees.  These  are  the 
work  of  the  fall  webworm.  The  eggs  of  this  moth,  300  to  500  in  num- 
ber, are  laid  in  patches  on  either  side  of  the  leaves  in  June.  The  larvae 
issue  from  June  to  August,  and  at  once  begin  their  web.  They  eat 
only  the  upper  surface  of  the  leaf,  leaving  the  veins  and  the  under 
surface  untouched.  The  young  caterpillar  is  pale  yellowish,  with  dark 
spots  along  the  sides  and  covered  with  scattered  hairs.    The  full-grown 


Fig.  20.— Hyphantria  cunea:  moths  and  cocoons.    (Howard). 


31 

caterpillar  is  velvety  black  above,  the  sides  have  two  yellow  stripes, 
and  between  them  are  many  blackish  patches  and  dots.  The  yellowish 
or  brownish  hairs  are  mostly  in  tufts  which  arise  from  tubercles  or 
warts.  Some  specimens  are  quite  pale;  others  very  dark.  In  Septem- 
ber or  October  the  caterpillar  is  ready  to  pupate,  and  descends  to  the 
main  branches  or  trunk  of  the  tree.  Here  it  makes  a  delicate  cocoon, 
within  which  it  changes  to  a  chrysalis.  The  insect  passes  the  winter 
in  this  stage,  and  the  moth  emerges  the  following  spring.  The  latter 
has  white,  sometimes  spotted  wings,  and  expands  about  an  inch  and  a 
half.  There  is  but  one  brood  each  year  in  the  North,  but  from  New 
York  city  south  there  are  two  broods,  the  caterpillars  of  the  second 
making  their  appearance  in  August. 

THE    BROWN-TAIL    MOTH. 

(Euproctis  chrysorrhea  Linn. — fig.  21.) 

This  insect,  at  present  confined  to  certain  parts  of  eastern   Massa- 
chusetts, is  such  a  dangerous  pest  that  all  interested  in  nursery  trade 


Fig.  21. — Euproctis  chrysorrhea.    Moths,  larvae,  and  cocoons.     (Howard.) 

should  be  able  to  recognize  it.  During  winter  their  small  but  very 
compact  webs  or  nests  attached  to  the  terminal  twigs  are  very  promi- 
nent objects  and  will  aid  in  distinguishing  the  species.  In  midsummer 
the  eggs  may  be  found  in  patches  of  two  or  three  hundred  attached 
to  the  under  side  of  a  leaf  near  the  tip  of  a  branch.  The  o^  mass  is 
covered  by  a  dense  Uryer  of  brown  hairs  from  the  tip  of  the  abdomen 
of  the  female.  The  young  hatch  in  August  and  eat  the  surface  of 
the  leaf.     As  soon  as  it  is  devoured  thev  draw  another  leaf  to  it,  until 


32 

in  the  fall  the}^  have  quite  a  tent.  On  the  approach  of  winter  they 
strengthen  their  tent  and  use  it  to  shelter  them  during  the  winter. 
In  spring  they  come  out,  eat  the  unfolding  buds  and  tender  leaves, 
and  thus  do  great  damage.  The  full-grown  caterpillar  is  about  1^ 
inches  long,  dark  brown,  mottled,  and  spotted  with  orange,  and  clothed 
with  reddish-brown  hairs  and  two  rows  of  dense  tufts  of  white  hair 
along  the  upper  side  of  the  body.  By  the  middle  of  June  the  cater- 
pillars are  ready  to  pupate,  and  each  makes  a  cocoon  attached  to  a 
terminal  branch,  or  sometimes  elsewhere  on  the  tree,  or  even  on  some 
other  object.  These  cocoons  are  often  close  to  each  other,  so  as  to 
form  quite  a  mass.  The  moths  emerge  in  a  few  weeks.  They  have 
white  wings,  and  the  females  a  brown  tip  to  the  abdomen.  There  is 
but  one  brood  each  year. 

THE    LEAF-CRUMPLER. 

(Mineola  indiginella  Zell.) 

The  presence  of  this  insect  is  easily  recognized  in  winter  by  the 
clusters  of  brown,  shriveled,  and  partly  eaten  leaves  fastened  together 
and  to  the  twigs  by  silken  threads.  Within  each  cluster  of  leaves  is 
a  curved  tube,  usually  sinuate  at  the  small  end,  and  within  this  tube  is 
the  small,  brownish  caterpillar  of  this  moth.  This  caterpillar  is  but 
half  grown.  In  early  spring  the  larva  cuts  loose  from  its  fastenings, 
crawls  with  its  case  out  upon  the  branches,  and  attacks  the  developing 
buds  and  young  leaves,  thus  causing  a  great  deal  of  injury.  The  cat- 
erpillar becomes  full  fed  by  the  middle  of  May,  and  is  then  of  a  green- 
ish color.  It  pupates  in  the  larval  nest,  and  the  moths  issue  in  June 
or  early  July.  The  eggs  are  deposited  in  July,  singly  on  the  leaves. 
The  young  larva,  upon  hatching,  starts  to  make  a  little  case  for  itself, 
which  it  enlarges  when  necessary.  They  feed  on  all  fruit  trees,  but 
are  partial  to  apple,  and  there. is  but  one  brood  annually. 

THE    WHITE-MARKED    TUSSOCK    MOTH. 

(Orgyia  leucostigma  S.  &  A. — %,  22.) 

The  caterpillar  of  this  moth,  which  does  great  damage  to  shade  trees 
in  cities,  sometimes  attacks  apple  and  other  fruit  trees.  The  adult 
insect  is  a  light-grayish  moth,  the  female  wingless,  the  male  with  ash- 
gray  wings,  expanding  about  li  inches,  and  the  antennae  are  feathered. 
The  eggs,  300  to  500  in  number,  are  laid  by  the  wingless  female  in  the 
fall  within  a  frothy  substance,  which  on  drying  becomes  hard  and 
brittle.  The  whole  is  a  very  prominent  whitish  mass,  often  situated 
partry  or  wholly  upon  the  old  cocoon.  In  Ma}^  the  }roung  larvae  hatch 
and  begin  eating  the  foliage.  The  larvae  are  full-grown  in  July,  and 
spin  their  slight  silken  cocoons,  attached  to  any  convenient  spot.  The 
full-grown  caterpillar  is  a  very  handsome  insect,  about  li  inches  in 


33 

length,  yellowish,   with  three  blackish  stripes  along  the  body,  and  a 

bright-red  head.     It  is  clothed  with  long,  scattered  hairs,  four  white 


HEIDEMflN  S.t 


Fig.  22. — Orgyia  U  ueostigma.    Various  stages;  eggs  at  h  and  k.     ( Howard.) 

tufts  on  the  anterior  part  of  the  body,  and  three  long  black  plumes, 
two  in  front  and  one  at  the  tip  of  the  body.     In  the  North  there  is 

but  one  brood  a  year, 
but  from  New  York  city 
south  there  are  usually 
two  broods,  the  caterpil- 
lars of  the  second  appear- 
ing in  early  August. 

THE    GIPSY    MOTH. 

(Porthetria  dispar  Linn — figs. 
23,  24,  and  25. ) 

Although     practically 

confined  to  certain  parts 

of  Massachusetts,  this  insect  is  quite  liable  to  spread,  and  all  interested 

in  orchards  and  nurseries  should  be  able  to  recognize  this  caterpillar. 

24842— No.  34:— 02 3 


Fig.  23. — Porthetria  dispar:  female  moth.     (Howard.) 


34 

The  eggs  to  the  number  of  400  to  500  are  deposited  in  clusters  attached 
to  trees,  fences,  etc.  Each  cluster  is  covered  with  yellow  hairs  from 
the  body  of  the  female,  which  causes  the  mass  to  resemble  a  piece  of 
sponge.  The  caterpillars  hatch  from  April  to  June,  and  feed  vora- 
ciously on  the  leaves,  mostl}T  at  night.  The  full-grown  caterpillar  is 
about  2  inches  long,  of  a  grayish,  mottled  appearance,  with  the  tuber- 


Fig.  24. — Porthetria  dispar.     Larva.     (Howard.) 

cles  on  the  anterior  part  of  the  bod}^  blue,  and  those  on  the  hinder  part 
of  the  body  red,  all  giving  rise  to  long  yellow  and  black  hairs.  When 
the  caterpillars  are  about  half  grown  they  begin  to  crawl  down  the  tree 
to  the  ground  in  early  morning,  and  ascend  again  for  feeding  in  the 
evening.     B37  July  they  are  ready  to  pupate  in  a  thin  cocoon  fastened 


Fig.  25. — Porthetria  dispar.    Chrysalis.     (Howard.) 

to  the  trunk  of  the  tree,  to  a  fence,  or  other  convenient  object.  The 
pupal  period  is  about  ten  days,  and  the  moths  issue  in  August. 
The  female  moth  has  whitish  wings  with  several  black  spots,  notably 
around  the  outer  margin.  The  male  is  brownish,  with  darker  undu- 
late lines  and  spots.  The  gipsy  moth  attacks  almost  every  sort  of  tree, 
and  there  is  but  one  brood  a  year. 


35 


CANKERWORMS. 

(Figs.  26,  27,  28,  and  29.) 

These  .slender,  bare  caterpillars  appear  on  apple  and  other  fruit 
trees  in  early  spring  and  eat  holes  in  the  leaves.  As  they  crawl  they 
loop  up  the  body,  and  are  thus  called  "measuring  worms"  or  "inch 
worms."     There  are  two  species  of  the  cankerworms,  their  habits,  how- 


Fig.  26. — Alsophila  pometaria:  a,  male;  b,  female, 
C,  '/,  details.     (Riley.) 


Fig.  27. — Alsophila  pometaria:  a,  I) 
/,  larva;  c,  d,  segments  of  same; 
(Riley.) 


'.    eggs; 
v.   pupa. 


ever,  being  similar.  The  eggs  are  laid  in  clusters  on  the  tree  in  the  fall 
and  early  winter,  with  the  fall  species  {AlsojphUa  pometaria  Harr.);  in 
March  or  April  with  the  spring  species  (Paleacrita  vemata  Peck). 
The  eggs  of  the  former  are  flattened  on  top;  those  of  the  latter  are 
rounded.     The  larva1   hatch   in  early  spring  and  at  once   feed  on  the 


Fig.  28. — Paleacrita  vemata:  a,  male;   b,  female, 
c,  d,  c,  details.     (Riley.) 


6     (£ 

Fig.  29. — Paleacrita  vemata:  a,  eater- 
pillar;  h,  egg;  c,  d,  segment  of 
caterpillar.     (Riley.) 


leaves.  When  full  grown  they  descend  to  the  ground  and  pupate 
therein,  the  moths  issuing  in  late  fall  or  wry  early  spring.  The 
females  are  wingless,  and  obliged  to  crawl  up  the  tree  to  deposit  eggs. 
The  males  have  large,  thin,  gray  wings.  There  is  but  one  brood  each 
year. 

THE    PEACH-TREE    BORER. 


{Sanninoidea  exitiosa  Say — fig.  30.) 

This  destructive  insect  is  readily  discerned  by  the  presence  of  a 
gummy  exudation  mixed  with  frass  and  excrement  at  or  near  the  base 
of  the  tree.  The  parent  moth  lays  the  egg^  singly  (from  May  to  July, 
according  to  latitude)  on  the  bark  of  the  tree,  usually  near  the  base. 
The  young  larva  burrows  into  the  bark  and  mines  between  it  and  the 


86 


sapwood  during  the  .summer  and  fall.  It  is  quiescent  during-  the 
winter,  but  resumes  feeding  in  the  early  spring,  reaching  full  growth 
by  May  or  June.  The  caterpillar  is  then  a  little  over  1  inch  in 
length,  soft,  and  pale  yellowish  in  color,  with  a  shining,  dark-brown 
head.  It  transforms  to  a  chrysalis  within  an  elongate  cocoon  just 
beneath  or  sometimes  outside  of  the  bark.     The  moths  emerge  in  May 


Fig.  30. — SSanninoidea  exitiosa:  a,  female;  b,  male;  c,  larva;   d,  e,  female  and  male  pupse;  /,  cocoon. 

(Marlatt.) 

or  June.  The  female  has  dark-blue  fore-wings;  the  male  has  clear 
ones.  It  primarily  attacks  peach,  but  sometimes  cherry  and  plum. 
There  is  but  one  brood  each  year. 

THE    PEACH    TWIG-BORER. 


(Anarsia  linealella  Zell. — fig  31. ) 

The  presence  of  this  insect  in  the  winter  is  quite  readily  known  by 
bits  of  frass  attached  to  the  bark,  often  at  the  crotches  of  branches  or 

twigs.  Each  bit  of  frass  covers 
the  entrance  to  a  small  burrow 
lined  with  silk,  within  which  the 
young  larva  of  this  insect  passes 
the  winter.  It  is  now  of  a  yellow- 
ish color,  with  the  head  and  thoracic 
segments,  as  well  as  the  last  seg- 
ment, almost  black.  Early  in 
spring,  when  the  leaves  are  coming 
out,  the  larvae  abandon  their  bur- 
rows and  attack  the  tender  leaf 
shoots,  boring  into  them  from  a 
point  a  little  below  the  apex,  and 
when  one  shoot  commences  to  dry 
the  larva  leaves  it  and  attacks  another.  In  about  two  weeks  the  larva 
is  full  grown,  and  pupates  in  a  slight  open  cocoon  attached  to  the 
bark  or  among  the  shriveled  leaves.  The  tiny,  grayish  moth  issues 
in  May.     Two  broods  follow  this,  the  larvae  boring  in  the  young  twigs 


Fig.  31.— Anarsia  lineatella:  a,  infested  twig 
b,  same  enlarged;  c,  larva  in  case,  d,  larva  en 
larged.    (Marlatt.) 


37 

or  sometimes  in  the  immature  fruit.  The  larva  from  the  second  brood 
makes  the  little  burrows  in  the  bark  in  which  the  insect  passes  the 
winter.     The  peach  twig-borer  feeds  on  all  stone  fruits. 

THE    BAGWORM. 

(Thyridopteryx  ephemerssformis  Haw. — figs.  32  and  33.) 

The  winter  cases  or  bags  of  this  insect,  1^  to  2  inches  long,  are  often 
seen  hanging  from  the  branches  of  shade  trees,  particularly  arbor- 


Fig.  S2.—Thyrulopteryx-ephemerseformis.    Cases;  d,  one  cut  open.     (Howard.) 

vitae,  locust,  and  basswood,  but  are  not  so  common  on   fruit  trees. 
The  adult  insect  is  a  moth;  the  female  winffiess:  the  male  with  four 


Fig.  33.— Thyridopteryx  ephemerseformis:  a,  larva;   6,  head  of  same;    c,  male  pupa;  d,  female  pupa, 
e,  adult  female;/,  adult  male— all  enlarged.     (Howard.) 

transparent  wings  and  a  black  body.     The  female  never  leaves  her 
case  alive,  but  in  the  fall  deposits  her  eggs  therein,  drops  out  and  dies, 


38 


Fig.  34. — Larva 
of  bud-moth. 
(Slingerland.) 


the  case  remaining  attached  to  the  tree  all  winter.  In  May  the  young 
hatch,  and  at  once  start  to  make  little  cases  for  themselves,  which  they 
enlarge  as  they  grow.  When  read}^  to  pupate,  the  caterpillar  fastens 
its  case  to  a  twig  and  transforms  to  the  chrysalis.  The  male  moth 
appears  in  August.     There  is  but  one  brood  a  year. 

OTHER   CATERPILLARS. 

On  the  apple  tree  in  winter  one  may  find  several  other  caterpillars 
in  various  stages  of  development.  One  of  them,  the  pistol-case  bearer 
(Coleophora  malivoreila  Riley),  is  a  small  larva  with  a 
dark  head.  It  carries  with  it  a  case  the  tip  of  which  is 
curved  over,  the  whole  about  one-eighth  inch  long.  It 
feeds  on  the  buds  and  leaves  in  spring.  In  the  fall  it 
fastens  itself  securely  to  the  twig,  and  thus  passes  the 
winter  in  an  immature  condition. 

Another  is  the  cigar-case  bearer  (Coleophora  Jletc her ella 
Fern.).  It  has  a  life  history  similar  to  the  preceding, 
but  its  case  is  straight,  not  curved. 
Both  feed  on  the  pear  and  quince. 
Small,  elongate,  white,  ribbed 
cocoons,  nearly  one-fourth  of  an 
inch  long,  often  in  clusters,  are  sometimes 
seen  on  apple  bark  in  winter.  They  indicate 
the  presence  of  the  apple-leaf  bucculatrix 
(B.  pomifoliella  Clem.).  In  spring  the  tiny, 
delicate  moths  issue  from  the  cases.  The  larvae 
mine  the  leaves.  There  are  two  broods  an- 
nually. 

Small,  inconspicuous  cases,  covered  with 
particles  of  dirt  and  bark,  are,  at  times,  found 
on  the  bark  of  the  apple  and  pear.  These  con- 
tain the  half -grown  larva  of  the  bud-moth 
(Tmetocera  ocellana  Schif.,  figs.  34  and  35). 
In  spring  the  larva  feeds  on  the  buds  and 
young  leaves,  webbing  the  leaves  in  a  bunch 
or  nest.  They  pupate  within  this  nest.  The 
moth  issues  in  Jul}^,  and  is  a  grayish  insect  with  a  creamy  white  patch 
on  each  fore-wing.  During  the  summer  the  young  larvae  partially 
skeletonize  the  leaves,  feeding  beneath  a  thin  silken  web.  As  winter 
approaches  they  migrate  to  the  twigs  and  form  their  hibernating  cases. 
There  is  but  one  brood  a  3^ear. 

COLEOPTERA  (BEETLES,  WEEVILS). 

Beetles  are  easily  known  by  the  hard,  coriaceous  fore-wings  that 
cover  and  protect  the  back  of  the  abdomen.  Both  in  the  larval  and 
the  mature  conditions  they  have  biting  mouth-parts,  and  injury  is 


Fig.  35.— Work  of  bud-moth 
larvse  in  opening  twigs. 
(Slingerland.) 


39 

sometimes  done  by  both  the  grub  and  the  beetle.  The  grubs,  to  reach 
the  adult  condition,  pass  through  a  complete  change  or  metamorphosis, 
like  caterpillars,  but  do  not  spin  a  silken  cocoon.  The  grubs  do  not 
have  the  prolegs  that  are  found  in  caterpillars.  The  forms  to  be 
noticed  below  may  be  arranged  as  follows: 

1.  Boring  in  the  twigs Apple  twig-borer. 

Boring  in  the  trunk  or  larger  branches 2. 

2.  .Making  tiny  circular  holes  in  the  bark Fruit-tree  bark-beetle. 

Making  a  sinuate  crack  or  depression Sinuate  pear  borer. 

Discolored  spots  on  the  bark Round-head  ami  flat-head  apple-tree  borers. 

THE    ROUND-HEADED    APPLE-TREE    BORER. 

(Saperda  c<ni(li<l<t  Fab. — tig.  3(5. ) 

Discolored  places  on  the  bark  near  the  base  of  the  trunk  may  indi- 
cate the  presence  of  this  borer.  Sometimes  the  bark  cracks  over  the 
burrow  and  allows  the  frassor  "sawdust"  to  drop  out,  and  often  there4 


a  b  c  d 

'  Fig.  36.— Saperda  Candida:   a.  b,  larva:  c,  beetle:  <1,  pupa,  enlarged.    (Chittenden.) 

is  some  exudation  of  sap.  Every  unnatural-looking  spot  near  the  base 
of  the  tree  should  be  examined.  The  adult  of  this  borer  is  a  grayish, 
long-horned  beetle  with  two  white  stripes  along  its  back.  They  appear 
in  June  and  July,  and  lay  their  eggs  in  little  slits  in  the  bark  made  by 
the  beetle  near  the  base  of  the  trunk.  The  larva?  or  grubs  soon  hatch 
and  bore  beneath  the  bark,  feeding  on  the  sapwood  and  inner  bark, 
and  making  flat,  shallow  cavities,  partially  filled  with  frass.  The 
grubs  are  nearly  cylindrical,  pale  yellowish  in  color,  and  when  full- 
grown  about  an  inch  long.  On  the  approach  of  winter  they  work 
downward,  often  below  the  surface  of  the  ground.  In  spring  they 
begin  to  feed  again,  boring  upward.  In  this  manner  they  feed  all 
summer  until  cold  weather,  when  they  again  hibernate.  In  the  spring 
they  resume  work,  but  now  they  bore  more  irregularly  and  further 
into  the  tree.     In  early  fall  they  bore  close  to  the  surface,  work  back 


40 

a  little,  and  then  pupate.  Winter  is  passed  in  this  condition,  and  in 
June  the  beetles  cut  circular  holes  in  the  bark  and  escape.  It  thus 
takes  three  years  to  reach  maturit}^  This  borer  also  infests  pear  and 
quince,  but  not  so  f  requentry  as  the  apple. 


"Fig.  37. — Chrysobothris  femoratg:  a,  larva;  b,  beetle; 
c,  head  of  male;  d,  pupa,  enlarged.  (Chitten- 
den.) 


THE    FLAT-HEADED    APPEE-TREE    BORER. 

(Chrysobothris  femorata  Fab. — fig.  37.) 

Discolored  spots  like  those  caused  by  the  round-headed  borer  may 
indicate  the  presence  of  this  insect.     They  are,  however,  often  found 

farther  up  the  trunk,  and  even  on 
the  larger  branches.  The  adult  is 
a  dark,  metallic  beetle,  rather  flat, 
and  about  one-half  inch  in  length. 
The  female  deposits  her  eggs  in 
crevices  of  the  bark  on  the  south 
side  of  the  tree,  usually  during 
June  and  July,  but  sometimes 
later.  They  apparently  prefer 
trees  that  are  weak  or  dying,  but 
also  attack  healthy  ones.  The 
young  larva  upon  hatching  eats 
through  the  bark  and  bores  be- 
neath the  surface,  leaving  a  flattened  burrow  filled  with  its  frass. 
Sometimes,  when  more  mature,  they  bore  deeper  into  the  sapwood. 
The  full-grown  larva  is  nearly  an  inch  in  length,  pale  yellowish  in 
color,  with  the  segment  next  to  the  head  greatly  enlarged  and  flattened. 
In  the  spring  it  bores  out  nearly  through 
the  bark,  then  moves  back  a  little  and 
pupates.  In  about  three  weeks  the  beetle 
cuts  an  elliptical  hole  in  the  bark  and 
escapes.  There  is  one  brood  each  year. 
It  attacks  apple,  pear,  cherry,  plum,  and 
quince. 

THE    SINUATE    PEAR   BORER. 

(Agrilus  sinuatus  Oliv. — figs.  38  and  39.) 

The  larva  of  this  insect  bores  long,  sinu- 
ate galleries  beneath  the  bark  and  sapwood 
of  pear,  killing  the  wood  and  causing  the 
bark  above  to  crack.  The  elongate  bronzy 
beetle  makes  its  appearance  in  May  or  early  June,  and  lays  its  eggs 
in  crevices  of  the  bark.  The  slender,  whitish  larva  burrows  beneath 
the  bark,  always  downward.  In  the  fall  the  larva  becomes  dormant, 
and  is  then  about  1  inch  long,  quite  flat,  whitish  or  yellowish  in  color, 


Fig.  38. — Agrilus  sinuatus:  a, 
b,  beetle;  c,  pupa,  enlarged.    (Origi- 
nal.) 


41 

with  a  brown  head,  and  the  segment  next  to  the  head  much  enlarged. 
In  spring  the  larva  resumes  feeding  and  makes  broader  burrows  tban 
in  the  first  year.  In  late  summer  or  early  fall,  when  full  fed.  it 
bores  about  one-fourth  inch  into  the  wood,  and  there  forms  an  elon- 


FlG.  39. — Work  of  AgrUus  sinuatus,  reduced.     ^  Smith.) 

gate  cell  parallel  with  the  bark  and  connected  to  the  outside  by  an 
exit  hole.  Within  this  cell  it  winters,  pupates  in  April,  and  the 
beetle  issues  in  May  or  June.  It  thus  takes  about  two  years  to  reach 
maturity. 


42 


THE    FRUIT-TREE    BARK-BEETLE. 


(Scolytus  rugulosus  Ratz. — fig.  40.) 

Small  circular  holes  in  the  bark  of  fruit  trees  indicate  this  insect, 
known  also  as  the  " peach  bark-borer"  or  " shot-hole  borer."     The 


ct  led 

Fig.  40. — Scolytus  rugulosus:  a,  b,  beetle;  c,  pupa;  d,  larva;  all  enlarged.     (Chittenden.) 

adult  insect,  a  tiny  black  beetle,  appears  in  the  latter  part  of  March  to 
the  middle  of  May,  and  burrows  through  the  bark.  Between  the  bark 
and  sapwood  the  female  makes  a  burrow  and  lays  her  eggs  along  each 


Fig.  41. — Amphicerus  bicaudatus:  a,  beetle;  b,  pupa;  c,  larva;  d,  winter  burrow;  e,  larval  gallery;  /, 

work  in  grape.     (Marlatt.) 

side.     The  young  upon  hatching  bore  away  from  the  parental  burrow, 
and  in  about  three  weeks  are  ready  to  pupate  at  the  end  of  the  gallery. 


43 

In  about  a  week  the  beetles  bore  out  from  their  burrows.  The  result 
is  that  the  bark  is  loosened  and  sometimes  the  tree  girdled.  When 
the}T  attack  peach  there  is  a  great  exudation  of  sap  and  a  consequent 
weakening  of  the  tree.  There  are  two  and  probably  throe  broods  ;i 
year,  but  as  they  start  at  different  times  the  broods  become  mixed.  It 
attacks  all  kinds  of  fruit  trees,  and  prefers  trees  that  are  dying, 
diseased,  or  weakened  by  other  insects,  but  healthy  trees  are  not 
exempt. 

THE    APPLE   TWIG-BORER. 

(Amphicerus  bicaudatus  Say — fig.  41.) 

In  the  fall  and  winter  the  adults  of  this  insect  bore  into  twigs  of 
apple  and  other  fruits,  as  indicated  in  fig.  41,  J.  Cutting  back  from 
this  hole  one  will  find  this  borer  in  tin4  adult  state — a  cylindrical  brown 
beetle  about  one-third  of  an  inch  long.  These  holes  are  their  hiber- 
nating quarters.  In  the  spring  the  insect  works  in  grape  canes,  caus- 
ing the  withering  of  new  shoots,  as  indicated  at  tig.  41,  f.  In  the 
spring  the  beetles  emerge  and  insert  their  eggf<  in  diseased  or  dying- 
twigs  of  grape,  maple,  or  other  plants;  the  larva  bores  through  the 
center  of  the  twig  until  fall,  when  it  pupates.  The  beetle  issues  in  late 
fall,  and  there  is  but  one  brood  a  year.  It  attacks  chiefly  appie,  pear, 
peach,  plum,  and  grape. 

ACARINA  (MITES). 

The  mites  are  not  insects,  although  related  to  them.  They  are  rec- 
ognized by  lacking  the  distinction  between  the  head  and  thorax  and 
by  the  absence  of  antennae.  There  are  usually  four  pairs  of  legs. 
but  in  the  pear-leaf  blister-mite  and  its  allies  there  are  but  two  pairs. 
Besides  the  pear-leaf  blister-mite,  which  is  treated  below,  there  are 
often  found  upon  fruit  trees  in  winter  numbers  of  tiny,  roundish,  red 
eggs.  These  belong  to  a  mite  known  as  the  clover  mite  (Bryobia  />r<i- 
tensis  Gar.).  They  rarely  do  damage  to  fruit  trees  in  the  East,  but 
feed  on  clover  and  similar  plants. 

THE    PEAR-LEAF    BLISTER-MITE. 

(Eriophyes  pyi  i  Scheut.) 

This  is  a  microscopic  mite  about  one  one-hundred  and  fiftieth  of  an 
inch  long,  with  a  slender  bod}T  provided  with  two  pairs  of  legs  near 
the  head  end.  Although  each  mite  is  so  small  as  to  do  little  damage 
of  itself,  it  may  become  the  parent  of  a  vast  assemblage  capable  of 
doing  a  great  amount  of  injury.  During  the  winter  the  mites  remain 
hidden  between  the  bud  scales.  Early  in  spring  the  mites  move  to 
the  young  unfolding  leaves,  eat  through  the  under  surface,  and  feed 
on  the  interior  substance  of  the  leaf.  Here  the  mites  increase  a  thou- 
sandfold.    Some  of  these  mites  move  out  to  form  new  galls,  until  a 


44 


Fig.  42.— Rhagoletis  pomonella:  a,  oviposition  puncture  in  apple  skin;  b,  exit  hole  of  larva;  c,  d,  work 
of  larvae  in  apple;  e,f,  g,  details;  h,  egg.     (Harvey.) 


45 


leaf  becomes  thickly  spotted  with  them.  Their  feeding  causes  a 
thickening  of  the  leaf  at  that  spot,  commonly  called  a  blister  or  gall. 
This  blister  is  at  first  of  a  reddish  color,  but  it  gradually  turns  brown, 
and  finally  black.  In  early  fall,  when  the  leaves  ripen,  the  mites 
leave  their  galls  and  take  refuge  in  the  buds  for  the  winter. 

INSECTS  INFESTING  FRUITS. 

Although  few  of  the  insects  infesting  fruit  are  liable  to  be  trans- 
ported upon  nursery  stock,  several  of  them  arc  such  destructive  pests 
as  to  merit  the  attention  of  all  interested  in  horticulture. 

*  *  *  *  *  *  * 

The  codling  moth  (Carpoca/psa  pomonella  Linn.)  passes  the  winter 
as  a  caterpillar  in  a  cocoon  in  crevices  or  under  loose  pieces  of  the 
bark.  However,  they  are  not  apt  to  occur  on  nursery  trees.  The 
cocoon  is  made  of  whitish  silk 
and  partially  covered  with  bits 
of  bark  so  that  it  is  not  easily 
seen.  In  early  spring  they 
pupate,  and  the  moths  issue  to 
lay  their  eggs  on  young  apples. 
The  larva  bores  into  the  apple, 
usually  from  the  blossom  end, 
mines  to  the  core,  and  then, 
when  about  full-fed,  bores  to 
the  surface.  It  leaves  the 
apple  to  pupate  on  the  trunk 
or  larger  branches  of  the  tree. 
Some  issue  in  late  June  or  July 
and  again  lay  eggs  on  the 
apple,  making  a  second  brood. 
In  the  Northeastern  States  there 
is  but  one  brood  a  year.  The 
quinces. 

The  apple  maggot  {Rhagoletis  pomonella  Walsh,  tig.  ±'l)  is  a  two- 
winged  fly  that  appears  in  June  and  lays  its  eggs  just  beneath  the  skin 
of  apples.  The  white  maggots,  upon  hatching,  burrow  throughout  the 
apple  in  various  directions.  When  full-fed  the  maggot  drops  to  the 
ground,  under  which  it  pupates  and  emerges  as  a  fly  the  next  spring. 

The  cherry  fruit-fly  {Rhagoletis  cmgvlata  Loew.  tig.  48)  infests 
cherry  in  much  the  same  manner  as  the  apple  maggot  infests  apples, 
and  has  a  similar  life  history. 

The  plum  curculio  {Con,otrachelus  nenuphar  Herbst.)  is  a  small, 
gra}Tish  weevil  that  passes  the  winter  under  the  bark  of  a  tree  or 
among  rubbish.  In  spring  it  deposits  eggs  within  the  plum  (peach 
or  cherry)  and  then  cuts  a  crescentic  slit  in  the  skin  near  by.  The 
larva  or  grub  soon  hatches  and  feeds  in  the  fruit,  causing  it  to  ripen 


Pig.  iB.—Rfuigoletis  cingiUata.     (Slingerland). 

codling  moth  also  attacks  pears  and 


46 

prematurely  and  fall.  The  grub,  when  full -grown,  passes  into  the 
ground  and  there  pupates,  the  beetle  issuing  in  the  fall.  The  beetle 
has  a  peculiar  habit  of  dropping  from  the  tree  when  disturbed. 

The  quince  curculio  (Conotrachelus  crat&gi  Walsh.)  is  a  very  similar 
insect  to  the  plum  curculio.  It  is  the  cause  of  knotty  or  wormy 
quinces.  The  weevil  lays  her  eggs  in  little  pits  of  the  quince  eaten  by 
the  parent  for  that  purpose.  The  grubs  feed  in  the  quince  till  the 
early-  fall,  when  they  leave  it  and  burrow  beneath  the  ground.  Here 
they  pass  the  winter,  pupating  in  early  spring. 

The  pear  midge  (Diplosis  pyrivora  Riley)  is  a  tiny,  two- winged  fly 
much  like  the  Hessian  fly,  that  appears  in  the  spring  and  lays  its  eggs 
in  young  pears.  The  larvae  feed  near  the  core,  causing  the  fruit  to 
shrivel  and  drop.  When  full-fed  they  leave  the  fruit  and  pupate 
about  an  inch  or  so  beneath  the  surface  of  the  ground.  The  winter  is 
passed  in  this  condition,  and  the  flies  emerge  the  following  spring. 


o 


UNIVERSITY  OF  FLORIDA 


